Heathco Wireless Entry Alert Kit, 100 ft Operating, 3 Tones, White | Heath Zenith Entry Alert Kit, Ding, Ding-Dong, Westminster Tone, 75 dB, Plastic, White, Wired/Wireless: Wireless, 3.5 in W x 1.49 in D x 5.12 in H Dimensions, Surface Mounting, Includes: Battery, Chime and Door Sensor